I suppose you could also call any unique blend of grapes or vineyards a "proprietary blend", and there are wineries who use that phrase. In fact, there are thousands of unique blends in the wine world if we consider the possible variations of grape varieties, percentages used in the blend, and vineyard sourcing.
Roger has enjoyed a lengthy career in the wine trade as an importer and retailer, and at present he is an educator, speaker and consultant. He set up and managed Millesima USA, a New York merchant affiliated with a leading European company. Previously, he served as senior executive of importers Frederick Wildman & Sons. In recent years, Roger has judged wine competitions in Argentina, Turkey and China. Roger became one of America's first Masters of Wine in 1993.